This invention relates to a storage system that replicates application data between plural volumes.
In the field of SANs (Storage Area Networks) or NASs (Network Attached Storages) where integrated storages are accessed from plural servers through networks, current systems tend to be large-scaled and highly-functional.
As an example of a highly-functional system, a technique is known in which data of applications running on servers is replicated (copied) to remote places, or the like, using a remote copy function possessed by the storages, while continuing other tasks, thereby enhancing redundancy.
Also, in such a SAN or NAS, plural servers utilize plural storages, so there is a tendency that a storage system including the storages and the associated network will be large-scaled and complicated. In order to make efficient use of the storages, a technique, as disclosed, for example, in JP 2004-133897 A, is known in which a fault that occurs to the storages or the network for connecting the storages and the servers to each other is detected without delay.
In this conventional example, an event message from a device constituting the storage system is obtained, and a management console is informed of the fault according to the importance of the event message.
In the conventional example described above, however, there is a problem in that, although it is possible to identify the location at which the fault has occurred (i.e., the device to which the fault has occurred), it is impossible to know how replication carried out by the remote copy function has been influenced by the fault.
In other words, from the storage perspective, it is sufficient that an administrator administering the storage system (hereinafter referred to as the “storage administrator”) identifies in which device the fault has occurred and is able to make repairs to the device. On the other hand, an administrator administering tasks (applications) on the servers (hereinafter referred to as the “application administrator”) is required to grasp how the replication performed in units of the applications has been influenced by the fault that occurred in the storage system, and how to maintain the consistency of data.
However, when a fault relating to replication has occurred in a large-scaled storage system, even when the application administrator knows the location of the fault, it is extremely difficult for him/her to check how the fault affected replication relations of a volume of a storage that a specific application uses, and how each volume that is a replication destination of the volume has been influenced. Also, in an environment in which replication is performed for plural applications, there can occur a case where the same volume is used by two or more applications. In such a case, it can be extremely difficult for the application administrator to grasp the range of influence resulting from the fault that occurred in the storage system with respect to the replication relations.